Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention:
U.S. Ser. Nos. 09/575,141, 09/575,125, 09/575,108, 09/575,109.
The disclosures of these co-pending applications are incorporated herein by reference.
The following invention relates to a printhead assembly having a flexible printed circuit board to provide power and data to individual printhead modules in a printer.
More particularly, though not exclusively, the invention relates to a printhead assembly having a flexible printed circuit board for providing data and power connections to individual printhead modules in an A4 pagewidth drop on demand printhead capable of printing up to 1600 dpi photographic quality at up to 160 pages per minute. The flexible printed circuit board also has associated therewith a pair of busbars for carrying the power thereto.
The overall design of a printer in which the assembly can be utilized revolves around the use of replaceable printhead modules in an array approximately 8xc2xd inches (21 cm) long. An advantage of such a system is the ability to easily remove and replace any defective modules in a printhead array. This would eliminate having to scrap an entire printhead if only one chip is defective.
A printhead module in such a printer can be comprised of a xe2x80x9cMemjetxe2x80x9d chip, being a chip having mounted thereon a vast number of thermo-actuators in micro-mechanics and micro-electromechanical systems (MEMS). Such actuators might be those as disclosed in U.S. Pat. No. 6,044,646 to the present applicant, however, might be other MEMS print chips.
In a typical embodiment, eleven xe2x80x9cMemjetxe2x80x9d tiles can butt together in a metal channel to form a complete 8xc2xd inch printhead assembly.
The printhead, being the environment within which the assembly of the present invention is to be situated, might typically have six ink chambers and be capable of printing four color process (CMYK) as well as infra-red ink and fixative. An air pump would supply filtered air through a seventh chamber to the printhead, which could be used to keep foreign particles away from its ink nozzles.
Each printhead module receives ink via an elastomeric extrusion that transfers the ink. Typically, the printhead assembly is suitable for printing A4 paper without the need for scanning movement of the printhead across the paper width.
The printheads themselves are modular, printhead arrays can be configured to form printheads of arbitrary width.
Additionally, a second printhead assembly can be mounted on the opposite side of a paper feed path to enable double-sided high speed printing.
It is an object of the present invention to provide a printer assembly having a flexible printed circuit board and busbars for delivering power and data to printhead modules of the assembly.
It is a further object of the present invention to provide an improved printhead assembly.
The present invention provides a printhead assembly for a pagewidth drop on demand ink jet printer, comprising:
an array of printhead modules extending substantially across said pagewidth,
a flexible printed circuit board carrying data and power to said modules, the flexible printed circuit board also extending substantially across said pagewidth,
a pair of busbars electrically connected to the flexible printed circuit board and carrying power thereto, the busbars also extending substantially across said pagewidth.
Preferably said busbars are soldered to said flexible printed circuit board.
Preferably said flexible printed circuit board contacts individual fine pitch flex PCBs on each printhead module.
Preferably said flexible printed circuit board has a series of gold plated, domed contacts which interface with contact pads on said fine pitch flex PCBs.
Preferably the flexible printed circuit board extends from one end of the assembly for data connection.
Preferably said printhead modules are fixed to an elongate channel and an elastomeric ink delivery extrusion is situated between the modules and the channel and the flexible printed circuit board is sandwiched between the elastomeric ink delivery extrusion and the channel and extends around one edge of the extrusion to carry power and data to the printhead modules.
Preferably the busbars are situated between the flexible printed circuit board and the elastomeric ink delivery extrusion.
Preferably said gold plated, domed contacts and said contact pads are located alongside said printhead modules and are biased into mutual contact by a resilient force exerted thereon by said channel.
Preferably said flexible printed circuit board is bonded to the channel.
As used herein, the term xe2x80x9cinkxe2x80x9d is intended to mean any fluid which flows through the printhead to be delivered to print media. The fluid may be one of many different colored inks, infra-red ink, a fixative or the like.